Difference between revisions of "Part:BBa K117002"
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__NOTOC__ | __NOTOC__ | ||
<partinfo>BBa_K117002 short</partinfo> | <partinfo>BBa_K117002 short</partinfo> | ||
| − | The | + | ==AI-2 quorum sensing system== |
| + | The integral part of the AI-2 quorum-sensing (QS) system consists of a transporter complex, LsrABCD; its repressor, LsrR; and a cognate signal kinase, LsrK. | ||
Once uptaken into the cell, AI-2 will be phosphorylated under the effect of LsrK. Without the presence of AI-2, LsrA promoter is inhibited by the repressor, LsrR. Phosphorylated AI-2 will prevent LsrR from inhibiting this promoter, hence activating it so that the downstream sequence can be expressed. | Once uptaken into the cell, AI-2 will be phosphorylated under the effect of LsrK. Without the presence of AI-2, LsrA promoter is inhibited by the repressor, LsrR. Phosphorylated AI-2 will prevent LsrR from inhibiting this promoter, hence activating it so that the downstream sequence can be expressed. | ||
To prevent the cell from self-inducing this promoter, we must suppress its AI-2 producing capability. It can be done by knocking out LuxS, one of the vital gene required for producing AI-2. By doing that, LsrA promoter can only be activated under the presence of AI-2 from other sources than the host cell which is LuxS mutant (say, by contact with normal cells). | To prevent the cell from self-inducing this promoter, we must suppress its AI-2 producing capability. It can be done by knocking out LuxS, one of the vital gene required for producing AI-2. By doing that, LsrA promoter can only be activated under the presence of AI-2 from other sources than the host cell which is LuxS mutant (say, by contact with normal cells). | ||
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More information on AI-2 quorum-sensing (QS) system please refer to: | More information on AI-2 quorum-sensing (QS) system please refer to: | ||
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1952038 | http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1952038 | ||
| + | ==Important notice:== | ||
| + | *This part is only the promoter region of LsrA gene which is normally inhibited by LsrR. It is NOT the entire LsrA gene. | ||
| + | *It is INDIRECTLY induced by AI-2, through a complex network involving LsrK,LsrR. | ||
| + | ==How this promoter works:== | ||
| + | By ligating LsrA promoter with a protein coding sequence downstream, we can regulate the expression of that protein by AI-2 as the inducer. To prevent self-inducing by the host cell, the plasmid must be transformed into cell with LuxS gene knocked out. | ||
<!-- Add more about the biology of this part here | <!-- Add more about the biology of this part here | ||
Revision as of 17:30, 7 October 2008
LsrA promoter (indirectly activated by AI-2)
AI-2 quorum sensing system
The integral part of the AI-2 quorum-sensing (QS) system consists of a transporter complex, LsrABCD; its repressor, LsrR; and a cognate signal kinase, LsrK. Once uptaken into the cell, AI-2 will be phosphorylated under the effect of LsrK. Without the presence of AI-2, LsrA promoter is inhibited by the repressor, LsrR. Phosphorylated AI-2 will prevent LsrR from inhibiting this promoter, hence activating it so that the downstream sequence can be expressed. To prevent the cell from self-inducing this promoter, we must suppress its AI-2 producing capability. It can be done by knocking out LuxS, one of the vital gene required for producing AI-2. By doing that, LsrA promoter can only be activated under the presence of AI-2 from other sources than the host cell which is LuxS mutant (say, by contact with normal cells).
More information on AI-2 quorum-sensing (QS) system please refer to: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1952038
Important notice:
- This part is only the promoter region of LsrA gene which is normally inhibited by LsrR. It is NOT the entire LsrA gene.
- It is INDIRECTLY induced by AI-2, through a complex network involving LsrK,LsrR.
How this promoter works:
By ligating LsrA promoter with a protein coding sequence downstream, we can regulate the expression of that protein by AI-2 as the inducer. To prevent self-inducing by the host cell, the plasmid must be transformed into cell with LuxS gene knocked out.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]